Retrofitting: Future-Proofing the Built Environment

Regulating the temperature of buildings is one of the single largest contributors to global energy consumption.

In fact, the heating of buildings is responsible for 40% of worldwide energy use, according to the IEA.

Conversely, the UNEP has found that cooling them consumes 20% of the planet's energy resources, highlighting a major inefficiency in the built environment's ability to retain and repel heat – an issue only set to intensify as climate change leads to more extreme temperature fluctuations.

While expanding renewable energy capacity is part of the solution, a more immediate and often more sustainable approach lies in reducing energy demand itself.

Retrofitting, the process of upgrading existing buildings to enhance their energy performance, offers a direct path to achieving this. It is not about reinventing energy sources but about minimising energy waste.

Enhancing performance in existing buildings

In practical terms, retrofitting involves a range of interventions designed to improve a building's thermal efficiency. This can include enhancing insulation in walls and lofts, replacing outdated heating systems with modern alternatives and installing double or triple-glazed windows. A crucial, and often overlooked, aspect is sealing gaps and cracks that allow heat to escape.

The business case

The argument for retrofitting is compelling, particularly when considering that most buildings that will be in use by 2050 already exist.

Much of the 20th century’s architectural portfolio prioritised aesthetics over thermal performance, resulting in structures that are inherently inefficient. Demolishing and replacing every inefficient building is not a viable option from either an economic or an environmental standpoint.

Retrofitting bridges this performance gap, with the primary benefits broken down into three main areas: cost, comfort and carbon reduction.

While outcomes vary between projects, retrofitting could contribute to a reduction in a property's energy bills by 30-50%. A notable example is the Empire State Building, which saw its energy consumption fall by 38% following a major retrofit initiative.

Although initial costs can be substantial, these projects are designed to deliver value over the long term.

According to The Quantum Group, ‘shallow’ retrofits, which involve less intensive upgrades, could see a return on investment in two to six years. For ‘deep’ retrofits, which are more comprehensive, the ROI period could be between 10 and 20 years.

Industry success

The cost of retrofitting work is dependent on the building type and the scope of the project. A basic residential retrofit that includes loft insulation and draught-proofing may cost between US$5,000 and US$15,000.

For commercial properties, more substantial interventions are often necessary, with costs ranging from US$50 to US$150 per square metre for upgrades that include facade improvements and the replacement of heating, ventilation and air conditioning (HVAC) systems.

These all-in-one systems are composed of several vents placed around a building, regulating the temperature of buildings by circulating air. Modern HVACs can function automatically to improve efficiency.

Several major organisations have already demonstrated the potential of ambitious retrofitting. Siemens upgraded its German headquarters in Munich, successfully preserving the building's historic character while cutting energy consumption by 40%.

Similarly, Microsoft undertook an extensive retrofit of its Puget Sound campus, reducing energy use by 30% across 125 separate buildings.

National governments are also promoting large-scale programmes. The Netherlands has initiated a comprehensive scheme aiming to retrofit one million homes by 2030, offering subsidies for insulation and heat pump installations.

In Sweden, the ‘Million Programme’ is focused on upgrading housing estates built in the 1960s and 1970s. This has resulted in energy reductions of up to 50% and has improved living conditions for residents.

These examples show that the transition to a low-carbon economy is heavily reliant on addressing the buildings we already have.